Navigation:  Tutorials > Measurement tutorials > DEWESoft 7.0  data acquisition, processing, analyzing and storage software Video acquisition

We have four basic types of cameras which are supported in DEWESoft:

So which camera to choose for a certain application? It is clear that the thermovision cameras have their special applications while the high speed cameras are used to acquire short triggered snapshots where we need extreme video rates to capture crashes, explosions and other fast events.

The decision between a good camcorder and a medium speed camera is not that easy. The main difference between these types of cameras and the high speed ones is that with the medium and low speed cameras we can continuously store video stream to the disk until we run out of disk space. We can also use software triggering on the video to reduce the amount of data or perform the online compression.

However, the system needs to have a good performance to stream video. We will need high performance hard disks and a very well built system, as we might still run to the limit of performance. We have to know that the typical VGA size image takes 300 kB. If we have 100 frames per second, we need to store 30 MB/s for one camera.

Clearly, if we need high speed video, we need to use either a Dewecam or Basler. Basler has a slightly higher speed (100 frames per second with VGA and up to 250 in reduced resolution), but Dewecam has a better picture quality with auto shutter, gain and white balance. A big advantage of both camera types is that they can be triggered from the analog card and therefore the data and video are perfectly aligned. The Dewecam has a small advantage because it implements the frame index in each picture, so it will work even in the case of a loss of trigger.

If 25 or 30 pictures per second are enough, we might consider using a camcorder. I would suggest progressive scan cameras, so as  not to have interlaced pictures.

Web cameras are usually low price/low speed/low quality, but are an extremely helpful tool to document the experiment. We had lots of feedback from customers telling us that a simple, even poor picture helped them to understand the recorded data much better.

In the following test we will see a basic difference between a web cam and a medium speed camera.